This has happend to me as well since a couple of days back. The watch is totally unusable now since i dont have time to charge it in the morning. When i check battery usage it says "notification" usage is approx 75%. Not sure what it should be but this seems a bit high. The only thing i have changed with my gear the last few weeks is to add the Samsung pay app. Can this be the cause?

My Gear Sport 3 is new from July this year, so only just 3 months old. The last 2 nights my watch has also drained whilst sleeping, I also know that it is fine as I have it set up to record my sleep. I get the notification to say I went to sleep on time, but when I wake up it is dead - switched off, with no battery life.

I have this morning done a reset on the Gear Sport, going to see if that works, I've only managed to get 43% charge in it to come to work with, so hoping it last until I get home.

But last night, I had it at 100% charge, as I left it to charge fully yesterday thinking it might be that it just needed full charge. This didn't work.

So I'm testing tonight to see if the reset worked.

Edit: I did do a weather app update in the last couple of days, not sure if it is app related drain, just not sure why it happens only during the night?

twice this week it has died on me suddenly. Last night I was fully charged and this morning as I got into work I was on 12% and now its completely gone.

This must be some sort of software issue... Samsung should just roll out the last working version. I usually get 4 days on a charge and now less than half a day. all this on a device I have had from new for less than 6 months

It's very odd. I'm not sure it can be a software issue as it's not draining oddly during the day and I haven't changed anything on my watch at all.

My watch is also draining completely. It's not simply running out more quickly, but actually losing 70% of battery in around 4 hours,having only used 30% in 18 hours. At 3am this morning and yesterday morning my watch was dead.